The present invention generally relates to dynamoelectric machines. More particularly, the present invention relates to an automated system and method for providing placement of insulation on lead wires of a dynamoelectric machine during a manufacturing process.
Induction motors typically include a stator and a rotor. The stator includes a hollow metallic core with a plurality of coils or windings running through the core. An alternating current is passed through these coils to generate an alternating magnetic flux field. The rotor includes a plurality of coils or windings in which an alternating current is induced by the alternating magnetic flux field of the stator. The end coils or end turns of the stator are grouped together at axial ends of the stator and are laced or stitched together to prevent interference with other components of a system. Also extending from axial ends of the stator are several groups of bare wire leads. The end turns may be coated with an epoxy or resin subsequent to stitching. This coating helps to reduce movement of the bare wires and provides an insulated barrier between the wires and other objects. Lacing in this case helps assure that the coils are tightly grouped together prior to coating.
Leads serve to supply electrical power and control signals to the stator during operation. The leads are typically insulated from one another with a non-electrically conductive shield or s sleeve, respectively, because each of the leads carry signals of varying electric potential. The non-electrically conductive sleeve provides the leads with protection from shorting in the event that two or more leads happen to cross. During manufacture of the stator, placement of the sleeves on each lead is done manually by an operator on the manufacturing floor. More particularly, the operator initially retrieves pre-cut sleeves and then manually threads each lead through its respective sleeve thereby providing the needed insulation. Manual sleeving of each lead wire is tedious, time consuming, and involves ongoing operator involvement during the stator manufacturing cycle.
Therefore, there is an unmet need in the art for a system and method for sleeving a lead wire which minimizes the amount of manual intervention needed so as to overcome the aforementioned deficiencies.
The present invention provides for a system and method for automating the sleeving process of lead wires. A stator of a dynamoelectric machine includes a hollow metal core with conducting wires orientated axially through the core. The conducting wires are grouped together into end windings which converge at upper and lower ends of the metal core. A series of lead wires extend from the upper end of the metal core and provide the stator with electric control and power signals. To electrically isolate the lead wires from one another, a sleeve is inserted over each lead wire. During the sleeving process, the lead wires are positioned to provide for grasping, and are insulated with sleeves. The present invention provides for an automated system to accomplish this process.
According to one aspect of the present invention, a system for sleeving the end lead wires includes using a gathering system to group the lead wires together. After the lead wires are sufficiently gathered together, a separating system is used to position the lead wires into predetermined locations. Alternatively, the separating system may only be used to space apart the lead wires and a sensory mechanism, such as a vision system, may be used to locate the position of the lead wires. Next, a grasping system will locate and secure a single lead wire between its finger clamps. The lead wire is then pulled away from group of lead wires and extended to a predetermined x, y, and z position in space.
A sleeving system is then used to insulate the lead wires. The sleeving system is fitted with an insulating sleeve positioned in a guiding channel. The sleeving system also includes a motor which operates to rotate a pair of internal rollers. The rollers, in turn, are operable to guide the sleeving system along the extended lead wire, thereby, pulling the lead wire through the guiding channel and through the sleeve. The sleeving system, then, separates along the centerline of the guiding channel and allows the sleeve to slide down the length of the lead wire. The lead wire is sufficiently insulated and the stator or the sleeving system may be rotated to repeat the sleeving process.